Slide fasteners are opening and closing tools for articles which are used in daily necessities such as clothing, bags, footwear and household goods, as well as in industrial goods such as water storage tanks, fishing nets and spacesuits.
FIG. 1 shows a structural example of a slide fastener. A slide fastener 10 is mainly composed of three components: a pair of elongated tapes 11; a number of elements 12 that are engaged portions of the fastener attached along one side edge of each tape; and a slider 13 for controlling the opening and closing of the fastener by engaging and disengaging the elements 12. Furthermore, the slide fastener can be provided with a top stop 14 and an opener 15 in order to prevent the slider 13 from falling off, and can attach a pull tab 16 as well as a pull tab cover 17 for fixing the pull tab 16 to the slider, on the surface of the slider 13.
The components of the slide fastener are molded components which can be produced by injection molding, and are known to be manufacturable from polyamides.
Japanese Patent No. 4517277 (Patent Document 1) discloses that polyamide resins can be used for slide fastener components. This document mentions polyamide 6, polyamide 66, polyamide MXD6, polyamide 6T, polyamide 11, polyamide 12 and the like as the polyamide resins.
WO 2013/098978 A1 (Patent Document 2) discloses a polyamide resin composition containing from 30 to 50% by mass of polyamide and from 50 to 70% by mass of reinforcing fibers, wherein 50% by mass or more of the polyamide is an aliphatic polyamide. Further, it discloses that in terms of improvement of a plating property, 80% by mass or more of the polyamide may preferably be the aliphatic polyamide.
WO 2015/155861 A1 (Patent Document 3) proposes to use an aromatic polyamide having a low melting point (from 200 to 250° C.), in order to improve strength after dyeing for small components such as a pull tab cover, a pull tab, a top stop, a bottom stop and elements.